SUPERHEAVY ELEMENTS AT GSI - INVESTIGATING EXOTIC NUCLEAR MATTER

The search for the next closed proton and neutron shells beyond (208)Pb has yielded a number of exciting results in terms of the synthesis of new elements at the upper end of the charts of nuclides, in a region of exotic high-Z nuclear matter. In particular, the results obtained at the Flerov Laboratory of Nuclear Reactions (FLNR) for a rich number of decay patterns for (48)Ca induced reactions on actinide targets have by now been confirmed for reactions on (238)U, (244)Pu and (248)Cm at GSI, and on (242)Pu at LBNL. These superheavy elements (SHE), however, are a nuclear structure phenomenon. They owe their existence to shell effects, an energy contribution of quantum mechanical origin to the nuclear potential, without which they would not be bound. Experimental activities in this field, apart from attempts to directly synthesize new elements, have to pursue reaction mechanism studies and, in particular, nuclear structure investigations to study the development of single particle levels towards the expected gap for the proton and neutron shell closure in the region of the spherical SHE.